Tool system and tool for mining machine

ABSTRACT

A tool system for a mining machine. The tool comprises a tool holder ( 12 ) and a cutting tool pick ( 14 ) with a cutting tip ( 16 ). The mounting end of the tool comprises a tapered shank ( 18 ) in a corresponding tapered socket ( 20 ) of the tool holder ( 12 ). There may be a wear plate ( 24 ) situated between the tool holder ( 12 ) and the tool ( 14 ). There may be further removable wear plates ( 30 ) positioned between the tool holder and the tool in the shank region, these wear plates may have lateral projections ( 29 ) engaging corresponding recesses ( 32 ) in the shank region of the body ( 12 ). All these wear plates may be sacrificial and are able to be replaced upon wear, thus less damage will occur to the shank region of the tool or the holder body. The tool assembly may further include a pin ( 42 ) which can engage both the tool and holder by extending through aligned openings, opening ( 40 ) in the tool holder and opening ( 38 ) in the tool. The pin may be resiliently held in place. A spray unit ( 25 ) extends through the wear part ( 24 ) and has an outlet ( 25   a ) to direct fluid toward the cutting tip ( 16 ).

The present application is related to Australian Provisional Patent Application No. 2010901134, the entire disclosure of which is incorporated herein by way of reference.

The present disclosure relates to a tool system for mining machines. The tool system has been developed primarily for use in longwall coal mining machines and iron ore mining machines. However, it will be appreciated that the tool system may also be used in other mineral winning machines, or indeed in excavation equipment, such as road headers, surface miners, continuous miners or tunnel boring machines.

Tool systems in known longwall coal mining machines are mounted on a shearer drum comprising a barrel around which extends a helical vane. The tool system is mounted on a radially outer edge of the helical vane and faceplate.

Tool systems in known iron ore mining machines are mounted directly on the cutterhead, commonly in a generally helical pattern along the length of the drum.

The tool system in known mining machines may include a spray unit for directing water toward a cutting end of the cutting tool. The spray unit is either threadedly engaged to a heel of the cutting tool or to the tool holder, or may be retained by a retaining device. A problem with known tool system however, is that the spray unit can blow out of engagement with the cutting tool or tool holder due to high spray water pressure or loss of the spray retaining device. Further, in embodiments where the spray unit is incorporated into the tool holder, the area around the spray unit is worn by the action of the base of the tool during operation of the mining machine.

Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

In a first aspect, the present disclosure provides a tool system for a mining machine, the tool system comprising:

a tool holder;

a tool having a cutting end for winning mineral from an ore body and a mounting end, the mounting end being adapted for engagement with the tool holder for securing the tool to the tool holder;

a set of removable plates having different lateral dimensions, each of the plates being engageable between the tool holder and the tool, such that a said plate of larger lateral dimension may be installed as the mounting end of the tool wears to take up an increased space between the mounting end and the tool holder caused by the tool wear.

The plates may each comprise a first lateral projection engageable with a corresponding first lateral indent on one of the tool holder and the tool. The plates may each be fastenable to one of the tool holder and tool. The first lateral projection may be resiliently snap-lockingly engageable with the first lateral indent. The removable plates may be engageable with a lateral edge of the mounting end of the tool.

The tool holder may include a socket for engagement by the mounting end of the tool. The mounting end of the tool may comprise a shank.

A second lateral projection may be provided on one of the tool holder and the tool, the second lateral projection being engageable with the other of the tool holder and the tool. The second lateral projection may be integrally formed in one piece construction with a body of the tool holder or may be in the form of a projection mounted to the tool holder. The second lateral projection may be provided on an opposite lateral side of the mounting portion of the tool to the first lateral projection.

A first laterally extending opening may be provided in the mounting end of the tool, the first opening being aligned with a second lateral opening in the tool holder when the tool is engaged in the tool holder, the second opening being open to an external surface of the tool holder, such that a pin may be engaged in both the first and second openings to secure the tool in the tool holder.

A pin may be resiliently slidably engaged in an opening in the tool holder and biased into engagement with an opening in the tool to secure the tool in the tool holder.

A recess may be defined by a space formed between the tool and the tool holder when the tool and the tool holder are engaged and a wear part may be adapted for engagement with the recess so as to be positioned between the tool holder and the tool. The wear part may be formed of a material that is less wear resistant than the tool holder, such that the wear part wears sacrificially to reduce wear of the tool holder. The wear part may be formed of a material that is more wear resistant than the tool, such that the tool wears sacrificially to reduce wear of the wear part. The wear part may be formed from a plastics material or from steel. The recess, and therefore the wear part, may be located adjacent a heel end of the tool. A spray unit may be engageable in an opening in the wear part and may have a outlet to direct fluid from the spray unit toward the cutting end of the tool. The spray unit may extend at least partially into a bore in the tool holder. A first laterally extending groove may be provided in the tool holder adjacent the bore and may align with a corresponding second laterally extending groove on the spray unit. The first and second grooves may together define a laterally extending opening for receiving a pin to lock the spray unit in the bore.

A line of weakness may be provided in the tool to define a predetermined failure point. The line of weakness may extend laterally across the tool. The line of weakness may be in the form of a groove in the tool. The line of weakness may be positioned so as to facilitate failure of the tool at a location that does not unduly inhibit removal of the tool from the tool, holder. The tool may comprise a laterally extending flange that is engageable by a lever to facilitate removal of the tool from the tool holder. The line of weakness may be positioned above the laterally extending flange such that the tool is adapted to fail at a position that leaves the laterally extending flange intact.

The tool holder may be adapted for connection to a rotatable head on a mining machine or may be integrally formed in a rotatable head on a mining machine. In some embodiments, the rotatable head may be, for example, a shearer drum on a mining machine for winning the likes of coal, potash, phosphate, salt or trona, or a cutter head on a mining machine. In other embodiments, the rotatable head may be, for example, a cutter head on a mining machine for winning minerals the likes of iron ore in harder ore bodies.

In a second aspect, the present disclosure provides a tool for a tool system for a mining machine, the tool comprising:

a cutting end for winning mineral from an ore body and a mounting end, the mounting end being adapted for engagement with a tool holder of the tool system for securing the tool to the tool holder;

a plate removably fastened to the mounting end, the plate comprising a first lateral projection for engaging a corresponding first lateral indent in the tool holder to facilitate securing of the tool to the tool holder.

The first lateral projection may be resiliently snap-lockingly engageable with the first lateral indent. The plate may be engageable with a lateral edge of the mounting end of the tool. Plates of various lateral dimensions may be provided for fastening to the mounting end of the tool, such that a said plate of larger lateral dimension may be installed as the mounting end of the tool wears to take up an increased space between the mounting end and the tool holder caused by the tool wear.

The mounting end of the tool may comprise a shank for engaging a socket in the tool holder.

A second lateral projection may be provided on the tool, the second lateral projection being engageable with the tool holder. The second lateral projection may be provided on an opposite lateral side of the mounting portion of the tool to the first lateral projection.

A first laterally extending opening may be provided in the mounting end of the tool, the first opening being alignable with a second lateral opening in the tool holder when the tool is engaged in the tool holder, the second opening being open to an external surface of the tool holder, such that a pin may be engaged in both the first and second openings to secure the tool in the tool holder.

A pin may be resiliently slidably engaged in an opening in the tool holder and biased into engagement with an opening in the tool to secure the tool in the tool holder.

A recess may be defined by a space formed between the tool and the tool holder when the tool and the tool holder are engaged and a wear part may be adapted for engagement with the recess so as to be positioned between the tool and the tool holder. The wear part may be formed of a material that is less wear resistant than the tool holder, such that the wear part wears sacrificially to reduce wear of the tool holder. The wear part may be formed of a material that is more wear resistant than the tool, such that the tool wears sacrificially to reduce wear of the wear part. The wear part may be formed from a plastics material or from steel. The recess, and therefore the wear part, may be located adjacent a heel end of the tool. A spray unit may be engageable with an opening in the wear part and may have a outlet to direct fluid from the spray unit toward the cutting end of the tool. The spray unit may extend at least partially into a bore in the tool holder. A first laterally extending groove may be provided in the tool holder adjacent the bore and may align with a corresponding second laterally extending groove on the spray unit. The first and second grooves may together define a laterally extending opening for receiving a pin to lock the spray unit in the bore.

A line of weakness may be provided in the tool to define a predetermined failure point. The line of weakness may extend laterally across the tool. The line of weakness may be in the form of a groove in the tool. The line of weakness may be positioned so as to facilitate failure of the tool at a location that does not unduly inhibit removal of the tool from the tool holder. The tool may comprise a laterally extending flange that is engageable by a lever to facilitate removal of the tool from the tool holder. The line of weakness may be positioned above the laterally extending flange such that the tool is adapted to fail at a position that leaves the laterally extending flange intact.

The tool holder may be adapted for connection to a rotatable head on a mining machine or may be integrally formed in a rotatable head on a mining machine. In some embodiments, the rotatable head may be, for example, a shearer drum on a mining machine for winning the likes of coal, potash, phosphate, salt or trona, or a cutter head on a mining machine. In other embodiments, the rotatable head may be, for example, a cutter head on a mining machine for winning minerals the likes of iron ore in harder ore bodies.

In a third aspect, the present disclosure provides a tool system for a mining machine, the tool system comprising:

a tool holder;

a tool having a cutting end for winning mineral from an ore body and a mounting end, the mounting end being adapted for engagement with the tool holder for securing the tool to the tool holder; and

at least three locking mechanisms for securing the tool to the tool holder, said at least three locking mechanisms comprising at least one of:

-   -   a first lateral projection on one of the tool holder and the         tool, and a corresponding first lateral indent on the other of         the tool holder and the tool, the first lateral projection being         engageable with the first lateral indent to facilitate securing         of the tool to the tool holder,     -   a first laterally extending opening in the mounting end of the         tool, the first opening being aligned with a second lateral         opening in the tool holder when the tool is engaged in the tool         holder, the second opening being open to an external surface of         the tool holder, such that a pin may be engaged in both the         first and second openings to secure the tool in the tool holder,         and     -   a pin resiliently slidably engaged in an opening in the tool         holder and biased into engagement with an opening in the tool to         secure the tool in the tool holder.

The tool holder may include a socket for engagement by the mounting end of the tool. The mounting end of the tool may comprise a shank.

The first lateral projection may be resiliently snap-lockingly engageable with the first lateral indent. The first lateral projection may be provided on a removable plate engageable with a lateral edge of the mounting end of the tool. Plates of various lateral dimensions may be provided. A plate of larger lateral dimension may be installed as the mounting end of the tool wears to take up the increased space between the mounting portion and the tool holder caused by the tool wear.

A second lateral projection may be provided on one of the tool holder and the tool, the second lateral projection being engageable with the other of the tool holder and the tool. The second lateral projection may be integrally formed in one piece construction with a body of the tool holder or may be in the form of a projection mounted to the tool holder. The second lateral projection may be provided on an opposite lateral side of the mounting portion of the tool to the first lateral projection.

A recess may be defined by a space formed between the tool and the tool holder when the tool and the tool holder are engaged and a wear part may be adapted for engagement with the recess so as to be positioned between the tool and the tool holder. The wear part may be formed of a material that is less wear resistant than the tool holder, such that the wear part wears sacrificially to reduce wear of the tool holder. The wear part may be formed of a material that is more wear resistant than the tool, such that the tool wears sacrificially to reduce wear of the wear part. The wear part may be formed from a plastics material or from steel. The recess, and therefore the wear part, may be located adjacent a heel end of the tool. A spray unit may be engageable in an opening in the wear part and may have a outlet to direct fluid from the spray unit toward the cutting end of the tool. The spray unit may extend at least partially into a bore in the tool holder. A first laterally extending groove may be provided in the tool holder adjacent the bore and may align with a corresponding second laterally extending groove on the spray unit. The first and second grooves may together define a laterally extending opening for receiving a pin to lock the spray unit in the bore.

A line of weakness may be provided in the tool to define a predetermined failure point. The line of weakness may extend laterally across the tool. The line of weakness may be in the form of a groove in the tool. The line of weakness may be positioned so as to facilitate failure of the tool at a location that does not unduly inhibit removal of the tool from the tool holder. The tool may comprise a laterally extending flange that is engageable by a lever to facilitate removal of the tool from the tool holder. The line of weakness may be positioned above the laterally extending flange such that the tool is adapted to fail at a position that leaves the laterally extending flange intact.

The tool holder may be adapted for connection to a rotatable head on a mining machine or may be integrally formed in a rotatable head on a mining machine. In some embodiments, the rotatable head may be, for example, a shearer drum on a mining machine for winning the likes of coal, potash, phosphate, salt or trona, or a cutter head on a mining machine. In other embodiments, the rotatable head may be, for example, a cutter head on a mining machine for winning minerals the likes of iron ore in harder ore bodies.

In a fourth aspect, the present disclosure provides a tool system for a mining machine, the tool system comprising:

a tool holder;

a tool having a cutting end for winning mineral from an ore body and a mounting end, the mounting end being adapted for engagement with the tool holder for securing the tool to the tool holder;

a recess defined by a space formed between the tool and the tool holder when the tool and the tool holder are engaged;

a wear part adapted for engagement with the recess so as to be positioned between the tool and the tool holder.

The wear part may be formed of a material that is less wear resistant than the tool holder, such that the wear part wears sacrificially to reduce wear of the tool holder. The wear part may be formed of a material that is more wear resistant than the tool, such that the tool wears sacrificially to reduce wear of the wear part. The wear part may be formed from a plastics material or from steel. The recess, and therefore the wear part, may be located adjacent a heel end of the tool.

A spray unit may be engageable in an opening in the wear part and may have an outlet to direct fluid from the spray unit toward the cutting end of the tool. The spray unit may extend at least partially into a bore in the tool holder. A first laterally extending groove may be provided in the tool holder adjacent the bore and may align with a corresponding second laterally extending groove on the spray unit. The first and second grooves may together define a laterally extending opening for receiving a pin to lock the spray unit in the bore.

The tool holder may include a socket for engagement by the mounting end of the tool. The mounting end of the tool may comprise a shank. One of the tool holder and the tool may have a first lateral projection and the other of the tool holder and the tool may have a corresponding first lateral indent that is engageable with the first projection to facilitate securing of the tool to the tool holder. The first lateral projection may be resiliently snap-lockingly engageable with the first lateral indent. The first lateral projection may be provided on a removable plate engageable with a lateral edge of the mounting end of the tool. Plates of various lateral dimensions may be provided. A plate of larger lateral dimension may be installed as the mounting end of the tool wears to take up the increased space between the mounting portion and the tool holder caused by the tool wear.

A second lateral projection may be provided on one of the tool holder and the tool, the second lateral projection being engageable with the other of the tool holder and the tool. The second lateral projection may be integrally formed in one piece construction with a body of the tool holder or may be in the form of a projection mounted to the tool holder. The second lateral projection may be provided on an opposite lateral side of the mounting portion of the tool to the first lateral projection.

A first laterally extending opening may be provided in the mounting end of the tool, the first opening being aligned with a second lateral opening in the tool holder when the tool is engaged in the tool holder, the second opening being open to an external surface of the tool holder, such that a pin may be engaged in both the first and second openings to secure the tool in the tool holder.

A pin may be resiliently slidably engaged in an opening in the tool holder and biased into engagement with an opening in the tool to secure the tool in the tool holder.

A line of weakness may be provided in the tool to define a predetermined failure point. The line of weakness may extend laterally across the tool. The line of weakness may be in the form of a groove in the tool. The line of weakness may be positioned so as to facilitate failure of the tool at a location that does not unduly inhibit removal of the tool from the tool holder. The tool may comprise a laterally extending flange that is engageable by a lever to facilitate removal of the tool from the tool holder. The line of weakness may be positioned above the laterally extending flange such that the tool is adapted to fail at a position that leaves the laterally extending flange intact.

The tool holder may be adapted for connection to a rotatable head on a mining machine or may be integrally formed in a rotatable head on a mining machine. In some embodiments, the rotatable head may be, for example, a shearer drum on a mining machine for winning the likes of coal, potash, phosphate, salt or trona, or a cutter head on a mining machine. In other embodiments, the rotatable head may be, for example, a cutter head on a mining machine for winning minerals the likes of iron ore in harder ore bodies.

Embodiments of a tool system according to the present disclosure will now be described, by way of example only, with reference t the accompanying drawings, in which:

FIG. 1 is a perspective view of an embodiment of a tool system in accordance with the present disclosure;

FIG. 2 is a side view of the tool system of FIG. 1;

FIG. 3 is a front view of the tool system of FIG. 1;

FIG. 4 is a top plan view of the tool system of FIG. 1;

FIG. 5 is a cross-sectional view taken along line 5-5 of the tool system of FIG. 4;

FIG. 5 a is an enlarged view of the circled portion of FIG. 5;

FIG. 6 is a perspective view of a front side of the tool of the tool system of FIG. 1;

FIG. 7 is a side view of the tool of FIG. 6;

FIG. 8 is a front view of the tool of FIG. 7;

FIG. 9 is a top plan view of the tool of FIG. 7;

FIG. 10 is a rear view of the tool of FIG. 7;

FIG. 11 is a perspective view of a rear end of the tool holder of the tool system of FIG. 1;

FIG. 12 is a perspective view of a front view of the tool holder of FIG. 11;

FIG. 13 is a front view of the tool holder of FIG. 11;

FIG. 14 is a side view of the tool holder of FIG. 11;

FIG. 15 is a top plan view of the tool holder of FIG. 11;

FIG. 16 is an exploded top plan view of the two parts of the tool holder of FIG. 11;

FIG. 17 is a perspective view of a wear part of the tool system of FIG. 1;

FIG. 18 is a front view of the wear part of FIG. 17;

FIG. 19 is a top plan view of the wear part of FIG. 17;

FIG. 20 is a side view of the wear part of FIG. 17;

FIG. 21 is a perspective view of the spray unit of the tool system of FIG. 1;

FIG. 22 is a side view of the spray unit of FIG. 21;

FIG. 23 is a longitudinal cross sectional view of the spray unit of FIG. 21;

FIG. 24 is a perspective view of a pin for securing the tool in the tool holder;

FIG. 25 is a perspective view of a pin for securing the wear part to the tool holder; and

FIGS. 26 and 27 are perspective views of the removable metal plate of the tool system of FIG. 1.

Referring to the drawings, and initially to FIGS. 1-5, there is shown a tool system for a longwall coal mining machine. The tool system 10 comprises a tool holder 12 and a tool 14. The tool 14 has a cutting end 16 for winning mineral from an ore body, a tapered mounting end comprising a shank 18 adapted for engagement in a correspondingly tapered socket 20 of the tool holder 12 for securing the tool 14 to the tool holder 12, a front end 14 a and a heel end 14 b. The cutting end 16 terminates in a tungsten carbide tip, which is retained by laid on in a slot or slug in a hole in the tool 12. The tool 14 has a streamlined shape, as shown in FIG. 4. As shown in FIG. 5, a recess 22 is defined by a space formed between the tool 14 and the tool holder 12 when 15 the tool and the tool holder are engaged, with the recess 22 being located adjacent a heel end 14 b of the tool 14. As shown in FIGS. 1, 4 and 5, a wear part 24 is adapted for captive engagement with the recess 22 so as to be positioned adjacent the heel end 14 b of the tool 14, between the tool 14 and the tool holder 12. The wear part 24 is shown in more detail in FIGS. 17-20, where it can be seen that retention projections 24 a extend from lateral edges of the wear part 24. As can be seen in FIGS. 11 and 12, corresponding recesses 12 c are provided in the tool holder 12, with the projections 24 a being engageable with the recesses 12 c to facilitate attachment of the wear part 24 to the tool holder 12. As shown in FIGS. 1, 4 and 5, a spray unit 25 is provided that has a lower end engageable in a bore 26 in the tool holder 12 and an upper end that extends through an opening 24 b in the wear part 24. The spray unit 25 is shown in more detail in FIGS. 21-23 and has an outlet 25 a to direct fluid from the spray unit 24 toward the cutting end 16 of the tool 14. A first laterally extending groove is 27 a provided in the tool holder 12 adjacent the bore 26 and, as shown in FIG. 5, aligns with a corresponding second laterally extending groove 27 b on the spray unit 25. The first and second grooves together define a laterally extending opening 27 for receiving a pin 28 to lock the spray unit 25 in the bore 26.

As shown in FIGS. 6-10, the tool 14 has a first lateral projection 29 formed on a removable plate 30 formed from spring, steel and engageable with a lateral edge 31 of the mounting end 18 of the tool 14. As shown in FIG. 5, the tool holder 12 has a corresponding first lateral indent 32 that is engageable with the first projection 29 to facilitate securing of the tool 14 to the tool holder 12. The first lateral projection 29 is resiliently snap-lockingly engageable with the first lateral indent 32. The plate 30 is connected to the mounting end 18 of the tool 14 by appropriate fasteners, such as buttons 33 that extend through holes 34 in the plate 30. The buttons 33 also gap fill the space between the mounting portion 18 of the tool 14 and the tool holder 12 to facilitate secure retention of the tool 14 in the tool holder 12. In other embodiments, however, the fasteners connecting the plate 30 to the tool 14 may comprise threaded bolts or press studs (not shown), or flanges formed on the plate 30 frictionally engaging corresponding slots in the tool 14. A set of plates 30 of various lateral dimensions is provided for use with the tool 14. A plate 30 of larger lateral dimension may be installed as the mounting end 18 of the tool 14 wears to take up the increased space between the mounting portion 18 and the tool holder 12 caused by the tool wear.

A second lateral projection, in the form of a button 36, extends from an opposite lateral side of the mounting portion 18 to the first lateral projection 29. The button 36 is engageable with an inner wall of the socket 20 of the tool holder 12 to urge the tool 14 toward the first lateral indent 34.

As best seen in FIGS. 5, 7 and 14, a first laterally extending opening 38 is provided in the mounting end 18 of the tool 14 and is .aligned with a second lateral opening 40 in the tool holder 12 when the tool is engaged in the tool holder. The second opening 40 is open to an external surface of the tool holder 12, such that a pin 42 may be engaged in both the first and second openings 38, 40 to secure the tool 14 in the tool holder 12.

As shown in FIG. 2, the tool 14 comprises a laterally extending flange 14 d that is engageable by a lever to facilitate removal of the tool 14 from the tool holder 12. A line of weakness, in the form of a groove 44, is provided in the tool to define a predetermined failure line extending laterally across the tool 14. The line of weakness 44 is positioned so as to facilitate failure of the tool 14 at a location that does not unduly inhibit removal of the tool 14 from the tool holder 12. Specifically, the line of weakness is positioned above the laterally extending flange 14 d, such that the tool 14 is adapted to fail at a position that leaves the laterally extending flange 14 d intact, so that a lever can be engaged with the flange 14 d even if the tool 14 has failed.

The wear part 24 is formed of a plastics material, such as polyoxymethylene (POM), typically known as Acetyl, Nylon or PTFE, that is less wear resistant than the tool holder, such that the wear part wears sacrificially to reduce wear of the tool holder. The plastics material of the wear part is also more wear resistant than the tool, such that the tool wears sacrificially to reduce wear of the wear part.

As shown in FIGS. 21-23, the spray unit 25 includes a fluid fitting 25 b, formed from nylon or a corrosion resistant metal, such as aluminium bronze. The outlet 25 a is provided at one end of the fitting 25 b and an inlet 25 c is provided at the other end of the fitting 25 b. The fitting 25 b is housed in a longitudinal opening or bore 46 in the tool holder 12. O-rings 25 d are provided around the fitting 25 b, at locations above and below the point of connection of the fitting 25 b to an inlet 48 in the tool holder 12, to provide a seal between the fitting 25 b and the tool holder 12. This arrangement of O-rings 25 d balances fluid pressure above and below the connection point between the fitting 25 b and the inlet 48 and stabilises the fitting 25 b in the longitudinal opening 46. The fluid fitting 25 b directs fluid supplied to the inlet 48 to the outlet 25 a for ejection toward the cutting end 16 of the tool 14. As shown in FIG. 5, the inlet 48 extends diagonally upwardly from a base of the tool holder 12 to intersect with the longitudinal opening 46.

As shown in FIG. 16, the tool holder 12 is formed in two pieces 12 a, 12 b for ease of manufacture. The two pieces 12 a, 12 b are secured together by fasteners, in the form of dowels 12 c and by welding.

In the illustrated embodiment, which is for use in a longwall coal mining machine for winning minerals the likes of coal, potash, phosphate, salt or trona, the tool holder 12 is adapted for connection to a rotatable shearer drum of the mining machine.

It will be appreciated that the provision of the wear part 24 between the tool 14 and tool holder 12 advantageously reduces wear of the tool holder 12 and tool 14 due to the wear part 24 wearing sacrificially. Moreover, when the wear part 24 becomes worn, it can be replaced without requiring the entire tool holder 12 or tool 14 to be replaced, thereby reducing expense and down time. Furthermore, providing opening 24 b in the wear part 24 for receiving the spray unit 25 creates a space between the spray unit 25 and the wear part 24 to facilitate replacement of the spray unit 25 without requiring removal of the wear part 24. Also, by locating the spray unit 25 in the tool holder 12, spray liquid is directed close to the tool tip 16. Prior art systems which do not position the spray on the tool holder lose this advantage. A further advantage of the illustrated tool system 10 is the provision of the line of weakness 44 in the tool 14, which promotes failure of the tool 14 at a convenient location. Without the line of weakness 44, there is a risk that the tool 14 will fail below the flange 14 d, which would make removal of the failed tool 14 from the tool holder 12 difficult. The streamlined shape of the tool 14 provides reduced flank wear, reduced power consumption and reduced dust creation.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the specific embodiments described above without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. Examples of possible modifications include, but are not limited to:

-   -   the tool holder 12 may be integrally formed in, or connected to         the rotatable cutting head of a mining machine for winning         minerals such as iron ore from harder ore bodies;     -   the pin 42 extendable through the first lateral openings 38, 40         in the tool 14 and tool holder 12 may be replaced or         supplemented by another locking mechanism, such as a pin,         staple, or buckle, that is resiliently slidably engaged in an         opening in the tool holder 12 and biased into engagement with an         opening in the tool 14 to secure the tool in the tool holder;     -   the wear part 24 and spray unit 25 may be integrally formed,         such that the wear part and spray unit are a single unit and are         replaced as a single unit;     -   the pin 42 and openings 38, 40 may be oriented at 90 degrees to         the orientation shown in the accompanying drawings; the recess         may be omitted and the removable plate 30 may be adapted to         retain the spray unit 24;     -   the removable plate 30 may be omitted;     -   the projection 29 on the removable plate 30 may be omitted;     -   the removable plate 30 may be fastened to the tool holder 12 and         snap-lockingly engageable with a corresponding lateral indent on         the tool 14;     -   the socket 20 of the tool holder 12 may be fitted with a gap         filling device, such as a sleeve, in which the tool 14 is         engaged, which may act as an adaptor to allow the tool holder 12         to be used with a differently configured tool;     -   the line of weakness may take an alternative form (eg. may be         defined by a reduced thickness portion of the tool body, a         hollow portion of the tool body, or a notch in the tool body);     -   the streamlined shape of the tool 14 may be omitted;     -   the wear part 24 may be formed from steel of other materials;     -   plate 30 being formed from other materials, such as stainless         steel or plastics (e.g. acetyl); and/or     -   the spray unit 25 may be omitted, in which case the opening 24 b         in the wear part 24 may be omitted. 

1-64. (canceled)
 65. A tool for a tool system for a mining machine, the tool comprising: a cutting end for winning mineral from an ore body, a mounting end comprising a shank complementary with and engageable in a socket of a tool holder, a laterally extending flange between the mounting end and the cutting end, the flange being engageable by a lever to facilitate removal of the tool from the tool holder, and a line of weakness in the tool defining a predetermined failure point, the line of weakness being positioned on the cutting end side of the flange, such that the tool is adapted to fail at a position that leaves the flange intact.
 66. A tool according to claim 65, wherein the line of weakness extends laterally across the tool.
 67. A tool according to claim 65, wherein the line of weakness is in the form of a groove in the tool.
 68. A tool according to claim 65, wherein the tool has a streamlined shape.
 69. A tool according to claim 65, wherein the tool is non-circular in transverse cross section.
 70. A tool according to claim 69, wherein the tool comprises a front end and a heel end, and opposite sides extending between the front end and the heel end, and wherein the cross section of a portion of the tool on the cutting end side of the line of weakness defines a shape having a width between the opposite sides and a length between the front end and the heel end, and wherein the width is less than the length.
 71. A tool according to claim 70, wherein the width reduces from a point of maximum width near the front end to a point of reduced width near the heel end.
 72. A tool according to claim 65, wherein the tool is connected to a rotatable head on a mining machine or is integrally formed in a rotatable head on a mining machine.
 73. A tool system comprising: a tool holder including a body having a socket therein; a tool comprising: a cutting end for winning mineral from an ore body, a mounting end comprising a shank complementary with and engageable in the socket of a tool holder, a laterally extending flange between the mounting end and the cutting end, the flange being engageable by a lever to facilitate removal of the tool from the tool holder, and a line of weakness in the tool defining a predetermined failure point, the line of weakness being positioned on the cutting end side of the flange, such that the tool is adapted to fail at a position that leaves the flange intact.
 74. A tool system according to claim 73, wherein the tool comprises an abutment surface adapted to engage a corresponding abutment surface on the tool holder when the tool shank is fully engaged in the socket, and wherein the laterally extending flange is spaced apart from the abutment surface of the tool toward the cutting end of the tool.
 75. A tool according to claim 73, wherein the line of weakness extends laterally across the tool.
 76. A tool according to claim 73, wherein the line of weakness is in the form of a groove in the tool.
 77. A tool according to claim 73, wherein the tool has a streamlined shape.
 78. A tool according to claim 73, wherein the tool is non-circular in transverse cross section.
 79. A tool according to claim 78, wherein the tool comprises a front end and a heel end, and opposite sides extending between the front end and the heel end, and wherein the cross section of a portion of the tool on the cutting end side of the line of weakness defines a shape having a width between the opposite sides and a length between the front end and the heel end, and wherein the width is less than the length.
 80. A tool according to claim 79, wherein the width reduces from a point of maximum width near the front end to a point of reduced width near the heel end.
 81. A tool according to claim 73, wherein the tool is connected to a rotatable head on a mining machine or is integrally formed in a rotatable head on a mining machine.
 82. A tool system according to claim 73, wherein the tool holder is connected to a rotatable head on a mining machine or is integrally formed in a rotatable head on a mining machine. 